1155123101 has 16 divisors (see below), whose sum is σ = 1274781888. Its totient is φ = 1037952000.

The previous prime is 1155123097. The next prime is 1155123103. The reversal of 1155123101 is 1013215511.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 1155123101 - 2² = 1155123097 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1155123103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 720701 + ... + 722301.

It is an arithmetic number, because the mean of its divisors is an integer number (79673868).

Almost surely, 2^1155123101 is an apocalyptic number.

1155123101 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1155123101 is a deficient number, since it is larger than the sum of its proper divisors (119658787).

1155123101 is a wasteful number, since it uses less digits than its factorization.

1155123101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2332.

The product of its (nonzero) digits is 150, while the sum is 20.

The square root of 1155123101 is about 33987.1019800159. The cubic root of 1155123101 is about 1049.2430223540.

Adding to 1155123101 its reverse (1013215511), we get a palindrome (2168338612).

It can be divided in two parts, 11551 and 23101, that multiplied together give a triangular number (266839651 = T₂₃₁₀₁).

The spelling of 1155123101 in words is "one billion, one hundred fifty-five million, one hundred twenty-three thousand, one hundred one".